• 제목/요약/키워드: Radiation effect

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방사선안전관리책임자 보수교육의 현황에 따른 정합성 판단 (Determination of Consistency according to the Status of Supplementary Education for Radiation Safety Management Managers)

  • 김승철
    • 대한방사선기술학회지:방사선기술과학
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    • 제47권1호
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    • pp.7-12
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    • 2024
  • Medical institutions wishing to install and operate diagnostic radiation generators must complete appointment training within one year of appointment based on the 「Medical Act」 and the 「Rules on Safety Management of Diagnostic Radiation Generator Devices」 which will come into effect on January 1, 2024. Additionally, You must receive supplementary education every three years from the date you received it. The strengthening of safety management for diagnostic radiation generators used in medical institutions means that although the radiation exposure that may occur when using diagnostic radiation generators is low, the risk of carcinogenesis may be higher than previously evaluated. In addition, safety management of diagnostic radiation generators can be said to be an essential requirement because it has been reported that the incidence of leukemia and other diseases is increasing in diagnostic radiation tests. However, the safety management training targets and programs for radiation exposure management operated by other organizations other than diagnostic radiation generators are significantly different. In addition, since the public institutions that are responsible for radiation safety management are divided, there is a risk of duplicative, excessive, and under-administrative application to medical institutions and educational institutions that install and operate diagnostic radiation generators. Therefore, we would like to determine their consistency by comparing domestic and foreign related cases and the provisions of the 「Medical Act」 and the 「Nuclear Safety Act」.

방사선 검출신호의 시계열 분석에 관한 연구 (A Study on Time Series Analysis for the Detector Pulses of Radiation)

  • 홍석붕;정종은;김용균;문병수;권기호
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.282-282
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    • 2000
  • The analysis of the radiation effect on matter has been performed using stochastic methods. Recently, It was discovered that the detector pulses of radiation can be analysed using deterministic method that utilizes the chaotic behaviour with an attractor found in a noise region. We acquired a time series for pulse tram of Am-241 using scintillation detector and reconstructed a phase space, then performed new analysis for the radiation detection signal by applying embedding theory, Lyapunov exponent, correlation dimension, autocorrelation dimension, and power spectrum.

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Development and Applications of Radiopharmaceutical “Milican inj.”

  • Ryu, Jei-Man
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-1
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    • pp.54-55
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    • 2003
  • Radiation therapy has been used for the cancer treatment externally or internally. The external radiation therapy has been widely used, but for the lack of its selectivity it requires strong radiation dose causing the dermal irritation and radiation effect of the normal tissues or organs. So we investigate non-clinical and clinical studies of “Milican inj.”, in which chitosan is chelated with 166-Holmium, as an anticancer agent for internal radiation therapy. (omitted)

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유한한 정사각형 기판을 가지는 마이크로스트립 패치 안테나의 방사 특성 (Radiation Characteristics of Microstrip Patch Antennas with a Finite Grounded Square Substrate)

  • 김태영;박재우;김부균
    • 대한전자공학회논문지TC
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    • 제46권6호
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    • pp.118-127
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    • 2009
  • 정사각형 기판의 크기가 패치 안테나의 방사 특성에 미치는 영향을 연구하기 위하여 마이크로스트립 패치 안테나를 제작하고 측정한 결과를 전산모의한 결과와 비교하였다. 전산모의한 방사 특성 결과와 측정한 방사 특성 결과가 잘 일치함을 볼 수 있었다. 기판의 크기가 패치 안테나의 공진 주파수와 대역폭에 미치는 영향은 작으나 방사패턴에 미치는 영향은 매우 큼을 볼 수 있었다. 기판 두께가 증가할수록 표면파의 발생이 증가하여 기판 크기에 따른 전방 방사 이득 변화 폭, 최대 방사가 일어나는 각도의 변화 폭과 방사패턴의 변화가 크게 발생한다. 기판 두께에 관계없이 기판 크기가 $0.8\;{\lambda}_0$ 일 때 전방방사 이득이 크고 전방방사와 후방방사 이득의 차이도 매우 크다.

Effect of UV Radiation on Early Growth of Korean Rice Cultivars(Oryza sativa L.)

  • Choi, Kwan-Sam;In, Jun-Gyo;Kang, Si-Yong;Bae, Chang-Hyu;Lee, Hyo-Yeon
    • 한국작물학회지
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    • 제44권3호
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    • pp.296-301
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    • 1999
  • The concerns on the crop damage by ultraviolet (UV) radiations is increasing owing to the decrease of their absorbing stratospheric ozone in the tropospheric. Cultivar differences on early growth of UV radiation among five Korean rice cultivars, four japonica types and one Tongil type (indica-japonica cross hybrid), were studied. Pot-seeded rice plants were grown under four different radiation conditions, i.e., visible radiation only, visible radiation with supplemented with high or low dose of UV-B (280~320 nm in wavelength) and UV-C (less than 280 nm in wavelength). The inhibitory degree on plant height, shoot and root weight and length of leaf blade and leaf sheath were determined at 40 days after seeding. UV-C showed the most severe inhibitory effect on the degree of biomass gain and leaf growth in most cultivars examined, followed by high UV-B and low UV-B. Among the cultivars used, the Kuemobyeo was the most sensitive cultivar and had not repair or showed resistance ability to continued irradiation of UV radiation. However, Janganbyeo and Jaekeon showed different responses that the elongation of leaf blades was promoted on 2nd and 3rd leaves and inhibited on 4th and 5th leaves but this inhibitory degree was reduced on 6 th and 7th leaves. Such tendency on leaf growth means that both cultivars had low sensitivity and most resistant ability to continued irradiation of UV radiation. While Tongil showed different response to enhanced UV radiation, ie., low UV-B promoted leaf growth but the inhibitory was severely increased by continued irradiation of high UV-B and UV-C, which means that Tongil had high threshold of UV radiation for response as an inhibitory light of plant growth. The results of this study indicate that the differences on sensitivity or resistant to the effects of UV radiation were existed among Korean rice cultivars.

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Parotid gland sparing effect by computed tomography-based modified lower field margin in whole brain radiotherapy

  • Cho, Oyeon;Chun, Mison;Park, Sung Ho;Oh, Young-Taek;Kim, Mi-Hwa;Park, Hae-Jin;Nam, Sang Soo;Heo, Jaesung;Noh, O Kyu
    • Radiation Oncology Journal
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    • 제31권1호
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    • pp.12-17
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    • 2013
  • Purpose: Parotid gland can be considered as a risk organ in whole brain radiotherapy (WBRT). The purpose of this study is to evaluate the parotid gland sparing effect of computed tomography (CT)-based WBRT compared to 2-dimensional plan with conventional field margin. Materials and Methods: From January 2008 to April 2011, 53 patients underwent WBRT using CT-based simulation. Bilateral two-field arrangement was used and the prescribed dose was 30 Gy in 10 fractions. We compared the parotid dose between 2 radiotherapy plans using different lower field margins: conventional field to the lower level of the atlas (CF) and modified field fitted to the brain tissue (MF). Results: Averages of mean parotid dose of the 2 protocols with CF and MF were 17.4 Gy and 8.7 Gy, respectively (p < 0.001). Mean parotid dose of both glands ${\geq}20$ Gy were observed in 15 (28.3%) for CF and in 0 (0.0%) for MF. The whole brain percentage volumes receiving >98% of prescribed dose were 99.7% for CF and 99.5% for MF. Conclusion: Compared to WBRT with CF, CT-based lower field margin modification is a simple and effective technique for sparing the parotid gland, while providing similar dose coverage of the whole brain.

흡수,방사 및 선형비등방 산란 매질을 포함하는 밀폐공간내의 자연대류- 복사열전달에 대한 수치해석 (Numerical Analysis of Natural Convection-Radiation Heat Transfer in an Enclosure Containing Absorbing, emitting and Linear Anisotropic Scattering Medium)

  • 차상명;김종열;박희용
    • 대한기계학회논문집
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    • 제16권5호
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    • pp.952-964
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    • 1992
  • 본 연구에서는 2차원 정사각형 밀폐공간내에 열복사를 흡수, 방사 및 비등방 산란하는 매질이 존재할 때 자연대류와 복사의 상호작용을 선형 비등방 산란을 가정 하고 복사열전달의 계산시 P-N 근사법을 이용하여 해석하였다. 수치계산을 통하여 Planck 수, 산란알베도, 광학두께, 벽방사율 및 비등방 산란이 유동 및 온도 특성 그리고 열전달에 미치는 영향을 조사하였다.

Hydrogen Bonding Effect on γ-Ray Irradiated Poly(vinyl alcohol) Hydrogels in Different Drying Conditions

  • Gwon, Hui-Jeong;Jo, Sun Young;Park, Eun Ji;Shin, Young Min;Choi, Jong-Bae;Park, Jong-Seok;Lim, Youn-Mook;Nho, Young-Chang;Kang, Phil Hyun
    • 방사선산업학회지
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    • 제6권1호
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    • pp.89-94
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    • 2012
  • Three-dimensional network hydrogels were prepared by ${\gamma}$-irradiation of aqueous solutions of poly(vinyl alcohol) (PVA) and glycerol (Gly). Oven-drying was used to measure the gel fraction (G), hydration (H) or swelling behavior (S) of the prepared hydrogels. This study made a hypothesis that hydrogen bonds due to addition of glycerol and change of dry states such as freeze-drying (FD), room-drying (RD) and oven-drying (OD) acts on the G, H, and S. Interesting results on the hydrogen bonding effect in the prepared hydrogels are monitored at different drying conditions. The FD samples have a higher G values with increase in glycerol content as compared with the OD and RD samples. The formation of strong hydrogen bonding network among Gly molecules and hydrogel matrix was considered as the main driving force, resulting in the changes in the G, H, and S of the hydrogels under different drying conditions.